plan-start

plan-start is a command for Claude Code from FlorianBruniaux/claude-code-plugins. It costs 39 tokens per session (1,615 once invoked), scanned A, original, MIT.

A five-phase planning command that analyzes product requirements, design, technical choices, research, and metrics before code is written. It records important decisions and produces an implementation plan and architecture decision records.

In plain words
What is it for?
Use it to turn a product request into a detailed plan, review design changes, document technical decisions, coordinate research, and define success measures.
Why use it?
It exposes missing or ambiguous requirements and architecture risks before they become expensive implementation or compliance problems.

Command for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: mentions CLAUDE.md.

Part of the pr-workflow plugin — 5 skills, 7 commands, 3 agents shipped together

Good fit Use it to turn a product request into a detailed plan, review design changes, document technical decisions, coordinate research, and define success measures.

Compare 6 commands from other repositories ↓
Install with agentmods
npx agentmods add commands/florianbruniaux/claude-code-plugins/plan-start
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/FlorianBruniaux/claude-code-plugins

Made for: Claude Code.

Or install pr-workflow, the plugin that ships this one along with the rest of its 5 skills, 7 commands, 3 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for plan-start

README.md
[![agentmods](https://agentmods.dev/badge/commands/florianbruniaux/claude-code-plugins/plan-start/github.svg)](https://agentmods.dev/commands/florianbruniaux/claude-code-plugins/plan-start)
Your own site
<a href="https://agentmods.dev/commands/florianbruniaux/claude-code-plugins/plan-start"><img src="https://agentmods.dev/badge/commands/florianbruniaux/claude-code-plugins/plan-start/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for plan-start

Your own site · 80×15
<a href="https://agentmods.dev/commands/florianbruniaux/claude-code-plugins/plan-start"><img src="https://agentmods.dev/badge/commands/florianbruniaux/claude-code-plugins/plan-start.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 39 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,615 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00039 $0.01615
Opus 5.5 $0.00016 $0.00646
Sonnet 5.5 $0.00008 $0.00323
Haiku 4.5 $0.00004 $0.00161

Measured 1mo ago against content hash d44183a5018c, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

plan-start scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/pr-workflow/commands/plan-start.md · 181 lines

How it starts

The opening of the file, as written. The whole thing — 181 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Plan Start — 5-Phase Planning

Analyze the request and produce a complete implementation plan through structured phases. No code is written. Every significant decision is recorded. Run /clear after this command before running /plan-validate.


Phase 1: PRD & Design Analysis

Step 1.1 — PRD Analysis

Skip if no PRD exists (refactor, infra change, bug fix).

Read all PRD files and docs/INFORMATION_ARCHITECTURE.md if present. Scan the codebase to understand current implementation status.

Surface findings in 3 buckets:

Missing requirements — acceptance criteria that are absent or incomplete Ambiguous requirements — items with multiple valid interpretations Compliance concerns — security, data privacy, API contract implications

For each finding: present options with concrete pros/cons. Discuss with user. Record every decision in the plan file under a ## Decisions section before moving on. Do not proceed past unresolved ambiguities.

Step 1.2 — Design Analysis

Skip if no UI changes are in scope.

Read: DESIGN_SYSTEM.md, existing UX ADRs, CLAUDE.md UX rules.

Produce specs for:

  • Screen inventory: new/modified screens, route placement, component reuse audit
  • State catalog: empty, loading, populated, error, and partial states for every interactive element
  • Interaction specs: user flows (happy path + alternates), focus/keyboard behavior
  • Animation specs: map each interaction to existing keyframes or specify new ones, include prefers-reduced-motion fallbacks
  • Responsive behavior: breakpoints, web/mobile divergence decisions
  • Accessibility: WAI-ARIA pattern selection, live regions, error visibility

Create Design ADRs for significant UX decisions (choice of interaction pattern, new animation convention, platform divergence). Record minor layout choices directly in the plan file.


Phase 2: Technical Analysis

Spawn 1-2 Explore agents for targeted codebase research. Run them in the background via Task tool.

Read the full file on GitHub · 181 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 1mo ago First seen · 181 lines · 39 tokens per session scan A d44183a5018c

Subscribe to this mod's changes

plan-start is a command published in the GitHub repository FlorianBruniaux/claude-code-plugins (42 stars, last pushed 1mo ago), licensed MIT. It adds 39 tokens to every session and 1,615 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-04.